Introduction

Dental development includes the formation of enamel and dentine and the eruption of both dentitions. Every healthy, normal child reaches a state of dental maturity when all the permanent teeth complete root formation and are functional. Tooth development can be assessed in many ways and as dental growth data are used by many disciplines, reference data are available in several ways to accommodate these needs. Orthodontists and pediatric dentists may need to assess the best age for treatment and require different information than anthropologists who might wish to compare growth or growth patterns between population or species. Tooth formation and eruption occur throughout the growth period from the middle trimester up to adulthood and this long maturation period provides a useful tool in assessing growth and maturation. Eruption of teeth is useful between 6 months and about 3 years for the deciduous teeth and about 5 to 16 years for the permanent teeth excluding the third molars. Assessing tooth formation and eruption from radiographs allows many more stages to be assessed; both crown and root formation stages as well as position of the developing tooth relative to the alveolar bone or occlusal levels. In addition developing teeth are less influenced by environmental factors than other growth systems (see Demirjian, 1986). This chapter is an extensive review of published studies in different human populations that document the timing of eruption of deciduous and permanent teeth into the mouth, eruption stages and tooth formation (excluding the third molar).